Stripper for intermittent spiral tube winder

ABSTRACT

AN IMPROVE STRIPPER FOR AN INTERMITTENT SPIRAL TUBE WINDER WHEREIN AN ARBOR ADVANCES WHILE ROTATING TO PERFORM A WINDING OPERATION AND THEREAFTER RETRACTS FROM THE ALREADY WOUND TUBE SO AS TO PRESENT AN OVERLAPPING PORTION SUITABLE FOR SEVERING-THE SEVERED TUBE BEING USEFUL AS A COIL FORM. THE IMPROVED STRIPPER OR GRIPPER INCLUDES ONE-WAY ROLLER CLUTCHES ARRANGED TO BEAR AGAINST THE SIDES A RECTANGULAR TUBE TO RESTRICT THE SAME FROM RETURNING WITH ARBOR.

ct- 1972 A. v. THOMAS 9 STRIPPER FOR INTERMITTENT SPIRAL TUBE WINDEROriginal Filed March 11, 1968 5 Sheets-Sheet 1 INVENTOR- ANTHONY THOMASATT'YS FIGZ Oct. 3, 1972 A. v. THOMAS 27500 STRIPPER FOR INTERMITTENTSPIRAL TUBE WINDER 5 Sheets-Sheet l FIG.5

Original Filed March 11, 1968 VFIGB INVENTOR. ANTHONY V. THOMAS ATT'YSOc t. 3, 1972 A, V.THOMAS Re. 27,500

STRIPPER FOR INTERMITTENT SPIRALTUBE WINDER Original Filed March 11,1968 5 Sheets-Shet 5 INVENTOR. ANTHONY v. THOMAS A. V. THOMAS STRIPPERFOR INTERMITTENT SPIRAL TUBE WINDER Oct. 3, 1972 5 Sheets-Sheet;

Origina i Fiie d March 11, 1968 INVENTOR. ANTHONY v THOMAS ATT'YS Oct.3, 1972 A. v. THOMAS STRIPPER FOR INTEHMITTENT SPIRAL TUBE WINDER 5Sheets-Sheet 5 I Original Filed March 11, 1968 IN VENTOR.

Q OE

ANTHONY v. THOMAS BY v flmgoyfl v United States Patent Oihce ReissuedOct. 3, 1972 27,500 STRIPPER FOR INTERMITTENT SPIRAL TUBE WINDER AnthonyV. Thomas, Prospect Heights, Ill., assignor to Precision Paper TubeCompany, Wheeling, Ill. Original No. 3,482,490, dated Dec. 9, 1969, Ser.No. 712,291, Mar. 11, 1968. Application for reissue Oct. 9, 1970, Ser.No. 79,715

Int. Cl. B31c 3/00 US. CI. 9380 5 Claims lvlatter enclosed in heavybrackets II] appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE An improved stripper for an intermittentspiral tube winder wherein an arbor advances While rotating to perform awinding operation and thereafter retracts from the already wound tube soas to present an overlapping portion suitable for severingthe severedtube being useful as a coil form. The improved stripper or gripperincludes one-Way roller clutches arranged to bear against the sides of arectangular tube to restrict the same from returning with the arbor.

Background of invention The invention finds particular utility inconnection with square-tube winders of the type found in'Jauch Patent-No. 1,625,471 and Macchione patent Reissue No. 25,820. Both of the Jauchand Macchione machines are of the intermittent type. Over the years,tube manufacturers have made use of both intermittent and continuoustube winders. Continuous tube winders are, for the most part, much morecomplex. The intermittent tube winders are characterized by anadvancing, rotating arbor which develops a wound length (6-8 inches inthe case of Iauch and 20-30 inches in the case of Macchione) after whichthe rotation stops, the wound tube gripped, and the arbor retracted tostarting position, after which the cycle is repeated. A critical elementin the operation of any intermittent winder is the stripping means thatrestrains the already formed tube from being retracted along with thearbor. Should simultaneous reaction occur, the winding operation mayhave to be stopped because of the possibility of overwinding, wrinklingof the tapes, etc. In the extreme, a jam or wadding of the tapes canoccurs which requires dismantling of the machines so as to realign thetapes.

Inasmuch as the tapes are wound relatively tightly on the arbor, asubstantial restraining force is necessary in the strippers to prevent ajoint retraction, i.e., to provide sufiicient gripping force on the tubeso as to overcome the friction between the tube interior and the arborso that the arbor may slidingly retract within the tube. In the past,the strippers have been characterized by the use of metal parts. Thesemetal parts tend to dig into the tube (in order to exert the necessaryrestraining force) and in some cases develop not only unsightly butunacceptable score marks. It will be appreciated that such forms areused to develop inductors wherein a large number of turns of wire areapplied and the value of the inductance is determined by the number andplacement of the wire turns. A distorted or otherwise damaged coil formcan develop an unacceptable variation in inductance.

With the order of magnitude of pressure that is exerted by the prior artstripping means, there results the possibility of scoring or burring thearbor itself, should the strippers contact a naked arbor. Once thisoccurs, the frictional engagement between the two is increased so thatthe desired slidability may be lost, possibly resulting in jams andexpensive and extensive down time and repair.

The principle concern, however, is that of preventing retraction of thetube with the arbor, i.e., the elimination of slack or backlash in thestripping mechanism. With mechanical arrangements of the nature taughtin both Jauch and Macchione, backlash of an unacceptably high valuedevelops relatively shortly after the machine is put into use. In theJauch machine, which makes use of ratchets and pawls as well as slidingand rotating knurled rollers, the various metal parts develop excessivebacklash. This, as will be pointed out hereinafter, may result inerratic grooving of the roller-receiving slots so as to render themachine unpredictably inoperable. In the Macchione machine, which hasthe advantage over Jauch in providing a longer tubular segment for eachcycle of the arbor, the greater restraining force needed has resulted ina complex stripper mechanism that is difficult to set up and maintain.

According to the invention, all of the foregoing difliculties areavoided through the unique usage of one-way roller clutches as thestripping means. By virtue of this arrangement, the advantage of theMacchione machine over the Jauch machine in providing longer tubesegments each cycle is preserved yet without the ditficulties in set up,maintenance and operation. Here it should be appreciated thatcontemporary production techniques result in the tubes having length ofthe order of about 24 inches. Thus a Jauch-type machine requires aboutthree cycles for such a tube. Notwithstanding the less efficientoperation of a Jauch-type machine, the same is preferred by some windersbecause of its more compact naturethis being tolerable where a quantityproduction is not critical.

It is therefore an object of this invention to provide an improvedstripper for both of the prior art type intermittent square tube windingmachines. Additionally, the invention provides a unique secondarygripping means for a Macchione-type machine, i.e., the one associatedwith the travelling cut-off.

Detailed description The invention is described in conjunction with twoembodiments in the accompanying drawing in which FIG. 1 is a fragmentarytop-plan view of the winding end of a Macchione-type machine;

FIG. 2 is a fragmentary enlarged top-plan view of the central portion ofFIG. 1;

FIG. 3 is a sectional view taken along the sight line 3-3 of FIG. 2 andshowing details of the basic gripper, i.e., the one employed forstripping the tube from the arbor during retraction of the latter;

FIG. 4 is a fragmentary sectional view taken along the slight line 44 ofFIG. 2 and showing in detail the gripping means associated with thetraveling cut-off;

FIG. 5 is an exploded perspective view of the traveling cut-off gripperof FIG. 4;

FIG. 6 is a top-plan View of the right-hand portion of FIG. 1 and thuscorresponds essentially to the right-hand portion of FIG. 2 but whereinthe arbor in FIG. 2 has been rotated so that the gripper portion in FIG.6 is essentially a side elevation of that seen in FIG. 2;

FIG. 7 is a perspective view of one of the one-way roller clutchesemployed in the grippers seen in the preceding views;

FIG. 8 is a transverse sectional view such as would be seen along thesight line 88 applied to the one-way roller clutch of FIG. 7;

FIG. 9 is an enlarged fragmentary detail of FIG. 8;

"FIG. is a top-plan view of a portion of a J auch-type lachine equippedwith the inventive gripper;

FIG. 11 is an enlarged detail of the gripper portion of IG. 10;

FIG. 12 is a bottom-plan view of the gripper seen in IG. 11',

FIG. 13 is a sectional view such as is seen along the ght line 1313 ofFIG. 12; and

FIG. 14 is a perspective view of the chassis portion of le gripper seenin FIGS. 1013.

In the illustration given and with particular reference a FIG. 1, thenumeral designates generally the frame E a horizontally elongatedmachine. Further details of [is machine may be seen in theabove-mentioned Maciione patent Reissue No. 25,820. The various primelover details at the extreme left end of the machine have een eliminatedfrom FIG. 1 for ease of description. The perational parts of the machinerelevant to the instant tvention include a traveling carriage generallydesignated l which provides a means for advancing an arbor 22. heextreme end of the arbor 22 is designated 22a in IG. 2. The carriage 21at its extreme left-hand end (not iown) may be coupled to a hydrauliccylinder for the urpose of advancing the carriage and arbor together (asL FIG. 10 to be described hereinafter). Stabilizing the .bor adjacentits unsupported end 22a is a traveling ripper mechanism generallydesignated 23this being arried by the carriage 21.

The arbor 22 is caused to rotate during its forward lovement, i.e.,during its travel to the right as shown. .otation of the arbor isachieved by means of the staonary gripper generally designated 24. Thestationary ripper or, more precisely, the tube stripper is positionedlong the machine length just forward of the tape appliitor positiongenerally designated 25. As can be best zen in FIG. 1, three tapes areprovided in angled relaon to the axial direction of the arbor and as thearbor )tates and is advanced, these tapes are wound in overtppingrelation to form a square tube. It will be apreciated that most of thetubes produced on intermittent iachines of this type for usage as coilforms have a crossaction but it will be appreciated that plural-sidedtubes f other configurations may be equally advantageously eveloped. Forthat purpose, the term rectangular is sed herein to designateplural-sided tubes whether they e triangular, rectangular, square,polygonal, etc.

In the operation of the apparatus thus far described, 1e carriage 21advances in a winding cycle toward the ight, meanwhile, the stationarystripper mechanism 24 otating the arbor 22 which is advancing with thecarriage 1. This causes the tapes T to be wound as at 25 and a 1becontinuously developed. As the carriage 21 reaches 1e right-hand end ofits stroke, rotation of the arbor 22 eases, the carriage 21 retracts(i.e., moves to the left) nd the arbor 22 is withdrawn from the tube 26leaving be same in cantilevered relation to the arbor. At that line, acut-off mechanism generally designated 27 and ssociated with theright-hand end of the carriage 21 PPCI'HIBS to transversely sever thetube--in a fashion decribed in greater detail in the above-mentionedReissue 'atent No. 25,820. Thereafter the cycle is repeated and hesevered tube segments are collected in a bin or other torage (notshown).

Stripper mechanism The stripper mechanism associated with the stationary;ripper 24 can be best appreciated from a consideration f FIGS. 2, 3 and6. Referring first to FIG. 3, the nuneral 28 designates a fragment of apedestal provided LS a stationary part of the frame 20, i.e., thepedestal 28 s rigidly integrated with the frame 20. Extending upvardlyfrom the pedestal 28 is a housing 29 which conains gearing (not shown)employed to rotate a chassis 30. As will be appreciated from what hasgone before, he chassis 30 is rotated intermittently, i.e., only duringthe advancement portion of the arbor reciprocating cycle. From acomparison of FIGS. 2 and 3, it is seen that the chassis 30 isessentially of an open-box construction, having four sides as at 31, 32,33 and 34. The sides are arranged in opposing pairs with the sides 31and 33 supporting a first pair of one-way roller clutches 35 and 36. Forthis purpose, the sides 31 and 33 are equipped with vertically-extendinggrooves as at 37. Received within the groove 37 are the journalsgenerally designated 38 (see FIG. 7) of a typical one-way roller clutch35. The journals of the first pair of roller clutches 35 and 36 areresiliently tied together by means of springs 39 and 40. Thus, thecentral portions 41 and 42 are urged together in clamping relation tothe tube 26. A similar arrangement is employed for the one-way rollerclutches 43 and 44 (see FIG. 3) extending between the opposed sides 32and 34.

The operation of the roller clutches as exemplified by the element 35 inFIG. 7 can be best appreciated from a consideration of FIGS. 7-9. Thejournal 38 extends from one end of the element to the other providing athrough shaft 45. This shaft is equipped with flats as at 46 (see FIG.7) so as to be non-rotatably received within the slots 37. Rotatablymounted about the shaft 45 is a needle-bearing cage 47 equipped withaxially elongated needle bearings 48. Clamped around the exterior of thecage 47 is a rubber sleeve 49 which provides the roller portion 41. Therubber sleeve 49 extends beyond the axial length of the cage 47 and issupported on spacers 50. The cage 47 consists of inner and outer partswith the outer part 51 being equipped with camming surfaces 52. Thus, asthe outer rubber sleeve 49 is attempted to be rotated in the directionof the arrow 53, the needlebearing elements 48 are forced clockwise,i.e., in the direction of the arrow 53 (see FIG. 9) so as to clutch theshaft 45 and thereby substantially immobilize the roller 41. Incontrast, when the sleeve 48 is subjected to a rotational force tendingto rotate the same in a counterclockwise direction (in the form picturedin FIG. 9), there is free rotation. The one-way roller clutches arearranged so that only 2-3 minutes of backlash rotation are requiredbefore the sleeve 49 is immobilized so as to restrict any tendency ofthe tube 26 to move in company with the arbor 22.

Traveling gripper Because of the length of tubing produced each cycle,it is desirable in a Macchione-type machine to provide a gripper toinsure that the tube 26 does remain immobile relative to the arbor asthe arbor 22 is advanced during a winding cycle. The traveling gripper23 is seen in FIGS. 2 and 4-6 and utilizes the same type of onewayroller clutches that were previously described in conjunction with thestripper mechanism 24. Optimum results have been obtained in thepractice of the invention utilizing roller clutches designated RC-061008of the Torrington Company of Torrington, Conn, these clutches also beingshown in US. Patents Nos. 3,184,020 and 3,194,368.

For the traveling gripper which grips the tube 26 on the forward strokeof the arbor but releases any clamping pressure thereon duringretraction of the arbor, I provide a subframe 55 (see FIGS. 2 and 5).The subframe 55 includes a pair of opposed plates 56 and 57 (see FIG. 5)each of which is equipped with a pair of angled, i.e., convergent slotsas at 58 and 59 in the plates 57 and 60 and 61 in the plate 56. Slidablymounted within opposing slots, i.e., 58 and 60, and 59 and 61 is a pairof roller clutches 62 and 63. As can be appreciated from FIG. 6, thejournal ends of the clutches 62 and 63 are interconnected by means of aspring 64, a similar spring being provided to couple the other journalends. The cooperating slots permit the parallel arranged roller clutches62 and 63 to move into clamping relation with a tube 26 on the arbor 22(see FIG. 4).

To achieve centering of the two clutches 62 and 63, I provide a pair ofsupplemental bars as at 65 in FIG. 5. The bars 65 are slotted as at 66and 67 to receive the journals on the ends of the clutches 62 and 63.The bars 65 are maintained in a predetermined position by means of ablock portion 68 slidably received within aslot 69 in the correspondingplate 56 or 57, as the case may be. By virtue of the cooperation of theblock 68 and the slot 69, the bar 65 maintains a predeterminedorientationone in which the length of the slots 66 and 67 isperpendicular to the axis of the arbor 22. As larger arbors or thickertapes T are used to form the square tubes 26. the block 68 moves in theslot 69 to accommodate outward movement of the journals of the clutches62 and 63 in the slots 60, 61, etc. The plates 56 and 57 are secured tothe housing 5 5 by virtue of Allen screws 70 passing through openings 71 into threaded bores 72 in integral flanges 73 (see FIG. 5). The bars65 are maintained in place by means of clips 74 which are threadablysecured to the adjacent plates in the manner indicated in 'FIG. 5. Thus,the above-mentioned sliding movement of the bars 65 is readilyaccommodated.

It will be seen that the traveling gripper 23 differs from thestationary stripper in utilizing only one pair of roller clutches. Theslots 5861 are also angled but this arrangement may also beadvantageously employed in the stripper 24. In the stripper 24, the fourplates 31-34 are maintained in orthogonal (i.e., mutually perpendicular)relation by means of their attachment to the gearing (not shown) Withinhousing 29. Additionally machine bolts 75 (see FIG. 2) secure the platesin the open-box construction shown and described. The spacers 50maintain the bearing cage 47 (and thus the sleeve 49) in centeredrelation with respect to the arbor 22. Although the shafts 45 areslidable axially with the cages 47 and spacers 50, there is no rotationof the shafts 4'5 tending to make them lose their seating within theslots 37. Further, the springs 39, 40, etc. serve as stops to preventany axial movement of the shafts 45.

When dissassembly is required, it is only necessary to remove thesprings 39, 40 from the journals 38 (more precisely from the annulargrooves 76see FIG. 7) and then slide the shafts axially out of one ofthe slots 37. Thereupon, the remainder of the roller clutch 35 (i.e.,the sleeve 49 with its internally received cage 47 and spacers 50) isreadily removable from the chassis 30 merely by moving the samelongitudinally of the machine.

However, even on jams or wrap-ups, the distorting tubing is readilyremoved without dismantling as was necessary previously-it only beingnecessary to overcome the spring bias and hold the clutches apart.

Modified Jauch machine Turning now to FIGS. 10l4, the numeral 120designates generally (in FIG. 10) the frame of a Jauch-type machine. Atthe extreme left-hand end is seen a cylinder and piston rod unit 121which is operative to advance and retract an arbor 122. Tapes T areautomatically wound around the arbor 122 as the latter is driven duringadvancement, i.e., movement to the right. In FIG. 10, the numeral 123designates generally a stripper means which is employed to provide arestraining action on the wound tube 124 as the arbor is retracted. Inother respects the machine shown is conventional.

To provide the novel stripping means, a subframe 125 (see FIG. 14) isprovided which is rotatably mounted within a pedestal arrangement 126(see FIG. 12) provided as part of the frame 120. It will be seen thatthe journals 127 at the ends of the subframe 125 are equipped with borescorresponding to the shape of the tube-equipped arbor 122 and it isintended that the subframe 125 rotate with the arbor 122.

To provide the desired gripping action, opposed pairs of clutch elementsare provided as at 128 and 129 in FIG. 13. Each pair of clutch elementshas corresponding ends resiliently coupled together as by springs 130(see FIG. 12). The journal ends of the clutch elements are non-rotatablysupported within slots 131 and 132 provided in the orthogonally relatedcover plates 133 provided on the subframe 125, the plates and subframebeing bolted together to constitute a chassis 134.

As one proceeds along the length of the chassis 136, it will be notedthat the pairs of clutch elements are displaced in proceeding from setto set. The actual number of sets (nine in the illustration given) maybe varied depending upon the amount of restraining force desired. Thesubframe is fabricated to provide alternating pairs of recesses 135,136, 137 and 138 (FIG. 14). These recesses receive the various clutchmembers, the subframe rigidifying the chassis 134.

In the operation of the Jauch-type stripper, the opposed pairs of clutchelements 128 and 129' resiliently grip the tube 124 and are, ofthemselves, virtually without backlash. This is in direct contrast tothe ratchet and pawl arrangement previously employed in Jauch wheresubstantial backlash or slack would occur as Wear progressed. For setup, the inventive arrangement is distinctly superior in requiring onlytwo springs for each pair (one at each end of a given clutch element) ascontrasted to four springs previously required. Notwithstanding theadvantages in case of set upand here it will be appreciated that amachine must be versatile in accommodating arbors of differentcross-sectional dimensions for different size tubessubstantialadvantages accrue from the inventive arrangement insofar as operationand maintenance are concerned. In the prior art construction, therollers actually rotated within the elongated chassis and, as a result,tended to develop grooves or pockets in the side walls of the slots 131and 132. Such grooves or indentations could literally result in acamming action to prevent the resilient mounting of the knurled rollersin the prior art construction, often resulting in jamming or wadding sothat substantial down time resulted. To remedy this, expensive repairswere required in the chassis. In contrast, the journals of the clutchelements here do not rotate so that there is no tendency to Wear groovesin the side walls of the supporting slots 131 and 132.

For larger sized arbors, the paired clutches merely position themselvesfurther apart in the slots and 131. Spacers bars 139, 140 are employedon each plate 133 to limit contraction of the springs 130 so that theentire chassis may be removed from its position about the arbor 124without derangement of the clutches. Also, means are provided at 141 and142 to vary the distance between spacer bars 139, 140 although thejournals normally do not contact these bars.

While in the foregoing specification a detailed description of theinvention has been set down for the purpose of illustration, manyvariations of the details hereingiven may be made by those skilled inthe art without departing from the spirit and scope of the invention.

I claim:

[1. In the apparatus for the intermittent conversion of tapes into atube of generally rectangular cross-section which includes ahorizontally-elongated frame, and elongated arbor of generallyrectangular cross-section mounted on said frame for rotation about theaxis thereof and for axial movement in the direction longitudinally ofsaid frame, means for advancing and retracting said arbor, means forsupplying a plurality of tapes to said arbor at an angle to the lengththereof, means on said frame for rotating said arbor during the advancethereof to helically wind said tapes on said arbor, and stripper meanson said frame located in a position forward of the points of tapeengagement with said arbor for coactive operation with said arbor inrestraining a tube from being retracted with said arbor when the latteris retracted, the improved stripper means comprising:

a chassis having an opening there through in which said arbor isreceived, said chassis having a plurality 7 of shaft-mounting slotstherein arranged to support resiliently interconnected elongated rollersin generally rectangular arrangement, and

a plurality of one-way, smooth-surface, cam-type roller clutches mountedon said chassis with each roller contacting a given side of said tubefor rolling contact therewith only upon arbor advance] [2. The apparatusof claim 1 in which gripper means -e movably positioned on said framefor movement with lid arbor and located a spaced distance forward ofsaid ripper means, said gripper means including a slotnipped blockhaving a pair of one-way roller clutches iapted to contact oppositesides of said tube in non-rotatale relation only on the forward strokeof said arbor, said lock being arranged and constructed to automatically:nter said roller clutches upon change in size of said lbC.]

[3. The structure of claim 1 in which said chassis in- .udes fourorthogonally related plates, said slots being rovided in each of saidplates and arranged to provide first pair of said clutches inlongitudinally offset relation a second pair of said clutches, saidclutches having fiat- :ned journals to non-rotatably slide in saidslots, and )ring means resiliently interconnecting corresponding annalsof each clutch of a given pair to urge the same \to gripping relationwith a tube ensleeved on said rbor.]

[4. The structure of claim 3 in which said clutches are uipped withthrough shafts providing said journals, said Jller clutches alsoincluding sleeve means positioned with- I said orthogonally relatedparts, said through shafts belg slidable within said sleeve means topermit ready dislaintling of said stripper means] [5. The structure ofclaim 3 in which said chassis inludes a unitary subframe within saidorthogonally related lates, said subframe having recess portionaccommodatlg said clutches, and spacer bar means on said chassis mitingthe movement toward each other of clutches in ach pair, said chassisaccommodating more than two airs of said clutches] 6. In the apparatusfor the intermittent conversion of tpes into a tube of generallyrectangular cross-section 'hich includes a horizontally-elongated frame,and elonated arbor of generally rectangular cross-section mounted n saidframe for rotation about the axis thereof and for xial movement in thedirection longitudinally of said time, means for advancing andretracting said arbor, teans for supplying a plurality of tapes to saidarbor at an ngle to the length thereof, means dn said frame for rotatingsaid arbor during the advance thereof to helically wind said tapes onsaid arbor, srtipper means on said frame located in a position forwardof the points of tape engagement with said arbor for coactive operationwith said arbor in restraining a tube from being retracted with saidarbor when the latter is retracted, and gripper means movably positionedon said frame for movement with said arbor and located a spaced distanceforward of said stripper means, said gripper means including aslot-equipped subframe having a pair of one-way roller clutches adaptedto contact opposite sides of said tube in non-rotatable relation only onthe forward stroke of said arbor, said subframe being arranged andconstructed to automatically center said roller clutches upon change insize of said tube.

7. The apparatus of claim 6 in which said clutches have flattenedjournals to non-rotatably slide in the slots of the slot-equippedsubframe and spring means resliently interconnecting correspondingjournals of each clutch to urge the clutches into gripping relation witha tube ensleeved on said arbor.

8. The apparatus of claim 6 in which the slot-equipped subframe includesa pair of spaced-apart plates, each plate being provided with a pair ofconverging elongated slots extending angularly with respect to the axisof the arbor, each of said clutches having a pair of journals with eachjournal received in one of said slots whereby the spacing bletween theclutches varies as the journals slide within the S OIS- 9. The apparatusof claim 8 in which the slots of each plate converge in the direction ofretraction of the arbor.

10. The apparatus of claim 8 including a bar mounted on each of saidplates, each bar being provided with an elongated slot which extendstrdnversely to the axis of the arbor and which slidably receives ajournal of each clutch, the bar being mounted on the associated platefor sliding movement in direction parallel to the axis of the arborwhereby axial movement of the bars varies the spacing between theclutches.

References Cited UNITED STATES PATENTS 7/1965 Macchione 93-80 4/1927Janch 93-80 BERNARD STICKNEY, Primary Examiner

